...And I say "different" because I actually liked most changes and don't actually mind the fact it didn't get much "new" stuff, but I'll get to that.
I'll split this into 4 sections: the Good, the Bad, the Ugly and the Suggestions. They'll also have to be split into 3 (possibly more) posts because 3000 characters is too few for any decent conversation on... almost anything that involves balancing systems.
But the TL;DR is: the changes are on the right direction, but the few things left unaddressed can essentially make the class useless in the perfect storm of situations. And that happens a bit too often for comfort. I've seen some of the same complaints around, but either too aimless, too simplistic, too angry and often without concrete suggestions. Also, I talk about more than just "DRK needs more self-healing".
The Good:
I think for the first time since the class's inception back in Heavensward, EVERY SINGLE BUTTON in our bar has a purpose and a semi-constant use (...except Living Dead, but we'll get to that). Quietus was a waste of Blood Bar / Delirium (and it was outclassed by Stalwart Soul + Flood of Shadow anyway), first-rework-Abyssal Drain had too long a cooldown to be reliable, Salted Earth's ground-targeting made many tanks forget to set it up, Delirium and Blood Weapon's mismatched cooldowns meant often DRK's delayed one's use so they could pop both together, etc etc.
Now everything has its use. The syncing of Delirium and Blood Weapon, plus potency changes, now mean Quietus weaved with Shadowbringer, Abyssal Drain and Flood of Shadow are our main AoE rotation, with an extremely powerful burst. Also, Delirium being changed to stacks rather than duration means we don't need to rely (...as much, I'll get to that too) on strict Skill Speed values to have optimal DPS.
Plus, the syncing means we have a reliable burst window that comes every 60 seconds, instead of "whenever the buffs' cooldowns align".
Also, removing the ground targeting from Salted Earth and giving it a secondary activation means we now use it far more easily and often (though I still think the cooldown is a tad too long).
Even though "the only two new things" we got from Endwalker was a two-charge "Super-Flood-of-Shadow" and a two-charge mini-Rampart, the under-the-hood refinements mean the entire kit is finally useful. We not only got the new skills, we also got the old ones that in the past weren't worth using.
The result is a versatile yet somewhat streamlined tank with lots of sustained damage, a big AoE burst and decent party utility.